The present invention is generally directed to devices implanted in the body and apparatus to replace a fluid of the implanted device with a therapeutic fluid.
The prior methods and apparatus for treating diseases of the eye can be less than ideal in at least some instances. For example, eye drops may have limited penetration of the external tissue of the eye, such that at least some therapeutic agents may not be delivered effectively with eye drops in at least some instances, for example high molecular weight therapeutic agents. Further, drops administered to the eye may not remain in the tear of the eye as long as would be ideal and can be washed away, for example when the patient blinks so as to provide less than ideal therapeutic benefit in at least some instance.
Implantable devices have been proposed to deliver treatment to the eye. However, in at least some instances, the therapeutic agent of the implantable device can be depleted, and the device may be removed or additional therapeutic agent placed in the device.
Prior methods and apparatus to place a therapeutic fluid in a device implanted in the eye can provide less than ideal results in at least some instances. For example, the amount of therapeutic agent placed in the device may be less than ideal in at least some instances. Further at least some of the prior methods to place of a therapeutic fluid in a device implanted in an eye may take longer than would be ideal. In at least some instances, the fluid placed initial in the device may be forced out of the therapeutic device, such that the amount of therapeutic agent placed in the treatment device can be less than ideal for sustained release of the therapeutic agent.
Work in relation to embodiment of the present invention also suggests that at least some prior injection apparatus may result in leakage during injection of the therapeutic agent. In at least some instances the injected fluid may comprise amounts of therapeutic agent that may be not be suitable for direct contact with tissue, such that leakage, or potential leakage, may limit available treatment options.
In light of the above, it would be desirable to provide improved methods and apparatus to place a therapeutic agent in a device implanted in the eye to provide improved treatments of diseases of the eye.